The United States says it is "disappointed" after India and Pakistan carried out rival missile tests.

Pakistan tested a new ballistic missile, capable of carrying a nuclear warhead, and India test-fired a surface-to-air short-range missile, known as Akash, hours later.

There is a charged atmosphere in the region and these tests can contribute to that atmosphere

Richard Boucher, US State Department

Authorities in Islamabad accused India of initiating an arms race.

India's foreign affairs spokeswoman, Nirupama Rao, described Pakistan's comment as an over-reaction.

The two nuclear-armed countries have kept about a million soldiers massed along their common border since an attack on the Indian parliament last December, which Delhi blamed on Pakistan-backed militants.

"We're disappointed that ballistic missile tests are occurring in the region," said US State Department spokesman Richard Boucher.

"There is a charged atmosphere in the region and these tests can contribute to that atmosphere, and make it harder to prevent a costly and destabilizing nuclear and missile arms race."

Britain has also said it is concerned about the tests.

"The UK continues to believe that restraint over testing by both sides particularly at a time of heightened tensions is in the long-term interests of India and the region," said Foreign Office minister Mike O'Brien.

Long range

Pakistan's surface-to-surface Shaheen-1 missile - also known as the Hatf-IV - has a range of up to 800 kilometres (500 miles).

India's Akash missile is capable of travelling 25 km off its east coast. It called the test a "routine" exercise.

Pakistan tested the Ghauri missile in May

But Pakistan's Information Minister, Nisar Memon told the AFP news agency: "We believe that India has done this to initiate an arms race which Pakistan has not at all indulged in."

The Indian Government called Pakistan's test a publicity stunt ahead of next week's general elections.

But the Indian Defence Minister, George Fernandes, said he was unconcerned.

"I don't see any reason why we should be worried about Pakistan conducting tests," he said.

"They have their missiles and they are testing them. We have our missiles and we also do tests."

Friday's tests come amid a resurgence in tensions between the South Asian arch-rivals over a spate of killings blamed on Pakistani-based militants during elections in Indian administered Kashmir.

Political message

India was given prior warning of the test, according to Pakistan's official news agency.

Islamabad also played down the significance of the test.

"This is purely a technical test and such technical tests are carried out from time to time," said Pakistani Foreign Ministry spokesman Aziz Ahmed Khan.

But some analysts said the test was a message to India.

"Whereas it is part of a continuous process to validate and revalidate their effectiveness, at this time it also has a political connotation," former army general and columnist Talat Masood told Reuters news agency.

India and Pakistan conducted several nuclear tests in 1998.

In May this year, Pakistan carried out a series of missile tests, as both countries came close to a war.